Lubricating fluids with enhanced energy efficiency and durability

ABSTRACT

The present invention comprises novel lubricating compositions, automotive gear lubricating compositions, and fluids useful in the preparation of finished automotive gear lubricants and finished gear oils, and methods of preparation thereof. The novel lubricating compositions of the present invention comprise a high viscosity fluid blended with a lower viscosity fluid, wherein the final blend has a viscosity index greater than or equal to 175. In another embodiment, the novel lubricating compositions of the present invention comprise a major amount of a blend of a high viscosity fluid blended with a lower viscosity fluid, wherein the final blend has a viscosity index greater than or equal to 175. Preferably, the high viscosity fluid comprises a polyalphaolefin and/or the lower viscosity fluid comprises a synthetic hydrocarbon. In another embodiment, the novel lubricating compositions of the present invention further comprise one or more of an ester, mineral oil and/or hydroprocessed mineral oil.

FIELD OF THE INVENTION

[0001] This invention belongs to the field of lubricating fluids andoils. More particularly, this invention relates to the use andpreparation of very high viscosity index lubricating fluids and finishedgear lubricants.

BACKGROUND OF THE INVENTION

[0002] Efforts to improve upon the performance of natural mineral oilbased lubricants by the synthesis of oligomeric hydrocarbon fluids havebeen the subject of important research and development in the petroleumindustry for at least fifty years and have led to the relatively recentmarket introduction of a number of synthetic lubricants. In terms oflubricant property improvement, the thrust of the industrial researcheffort on synthetic lubricants has been toward fluids exhibiting usefulviscosities over a wide range of temperature, i.e., improved viscosityindex, while also showing lubricity, thermal and oxidative stability andpour point equal to or better than mineral oil.

[0003] The viscosity-temperature relationship of a lubricating oil isone of the critical criteria which must be considered when selecting alubricant for a particular application. The mineral oils commonly usedas a base for single and multigraded lubricants exhibit a relativelylarge change in viscosity with a change in temperature. Fluidsexhibiting such a relatively large change in viscosity with temperatureare said to have a low viscosity index. Viscosity Index (VI) is anempirical number which indicates the rate of change in the viscosity ofan oil within a given temperature range. A high VI oil, for example,will thin out at elevated temperatures slower than a low VI oil. Theadvantage of VI rating is that it capsulizes the effects of temperatureas a single number. The viscosity index of a common paraffinic mineraloil is usually given a value of about 100. Viscosity index is determinedaccording to ASTM Method D 2270-93 [1998] wherein the VI is related tokinematic viscosities measured at 40° C. and 100° C. using ASTM Method D445-01.

[0004] The American Petroleum Institute defines five groups of basestocks. Groups I, II and III are mineral oils classified by the amountof saturates and sulfur they contain and by their viscosity indices.Group I base stocks are solvent refined mineral oils. They contain themost saturates and sulfur and have the lowest viscosity indices. Theydefine the bottom tier of lubricant performance. Group I stocks are theleast expensive to produce, and they currently account for about 75percent of all base stocks. These comprise the bulk of the“conventional” base stocks.

[0005] Groups II and III are the High Viscosity Index and Very HighViscosity Index base stocks. They are hydroprocessed mineral oils. TheGroup III oils contain less saturates and sulfur than the Group II oilsand have higher viscosity indices than the Group II oils do. Groups IIand III stocks perform better than the Group I base stocks do,particularly in measures of thermal and oxidative stability. Isodewaxedoils also belong to Groups II and III. Isodewaxing rids these mineraloils of a significant portion of their waxes, which improves their coldtemperature performance greatly. Groups II and III stocks are moreexpensive to produce than Group I stocks are, and account for about 20percent of all base stocks.

[0006] Group II and III stocks may be “conventional” or“unconventional.” Generally, “unconventional” base stocks are mineraloils with unusually high viscosity indices and unusually lowvolatilities. Group II and III solvent refined mineral base stocks are“conventional.” Compared to Group I solvent refined oils, hydroprocessedGroup II and III oils offer lower volatility, and when properlyadditized, greater thermal and oxidative stability and lower pourpoints.

[0007] Group IV consists of polyalphaolefins. Group IV base stocks offersuperior volatility, thermal stability, oxidative stability and pourpoint characteristics to those of the Group II and III oils with lessreliance on additives. Currently, Group IV stocks, the PAOs, make upabout 3 percent of the base oil market. Group V includes all other basestocks not included in Groups I, II, III and IV. Esters are Group V basestocks.

[0008] Polyalphaolefins (“PAOs”) comprise a class of hydrocarbonsmanufactured by the catalytic oligomerization (polymerization tolow-molecular-weight products) of linear α-olefins typically rangingfrom 1-octene to 1-dodecene, with 1-decene being a preferred material,although polymers of lower olefins such as ethylene and propylene mayalso be used, including copolymers of ethylene with higher olefins, asdescribed in U.S. Pat. No. 4,956,122 and the patents referred totherein. PAO products have achieved importance in the lubricating oilmarket.

[0009] The PAO products typically produced may be obtained with a widerange of viscosities varying from highly mobile fluids of low-viscosity,about 2 cSt., at 100° C. to higher molecular weight, viscous materialswhich have viscosities exceeding 100 cSt. at 100° C. [Note: PAOs arecommonly classified according to their approximate kinematic viscosity(KV) at 100° C. The kinematic viscosity of liquid is determined bymeasuring the time for a volume of liquid to flow a given distance undergravity. Dynamic viscosity can then be obtained by multiplying themeasured kinematic viscosity by the density of the liquid. The units forkinematic viscosity are 1 m²/s, commonly converted to cSt. orcentistokes (1 cSt.=10⁻⁶ m²/s) with 1 cSt. being the viscosity of waterat 0° C.]

[0010] PAOs may be produced by the polymerization of olefin feed in thepresence of a catalyst such as AlCl₃, BF₃, or BF₃ complexes. Processesfor the production of PAOs are disclosed, for example, in the followingpatents: U.S. Pat. Nos. 3,149,178; 3,382,291; 3,742,082; 3,769,363;3,780,128; 4,172,855 and 4,956,122. PAOs are also discussed inLubrication Fundamentals, J. G. PAO Wills, Marcel Dekker Inc., (NewYork, 1980). Subsequent to polymerization, the PAO lubricant rangeproducts are hydrogenated in order to reduce the residual unsaturation.In the course of this reaction, the amount of unsaturation is generallyreduced by greater than 90%.

[0011] Hydrocarbons generally, and in particular synthetic PAOs, havefound wide acceptability and commercial success in the lubricant fieldfor their superiority to mineral based lubricants. In terms of lubricantproperty improvement, industrial research efforts on syntheticlubricants has led to PAO fluids exhibiting useful viscosities over awide range of temperature, i.e., improved viscosity index, while alsoshowing lubricity, thermal and oxidative stability and pour point equalto or better than mineral oil. These relatively new synthetic lubricantslower mechanical friction, enhancing mechanical efficiency over the fullspectrum of mechanical loads and do so over a wider range of operatingconditions than mineral oil.

[0012] In accordance with customary practice in the lubricant arts, PAOshave been blended with a variety of additives such as functionalchemicals, oligomers and polymers and other synthetic and mineral oilbased lubricants to confer or improve upon lubricant propertiesnecessary for applications, such as engine lubricants, hydraulic fluids,gear lubricants, etc. Blends and their additive components are describedin Kirk-Othmer Encyclopedia of Chemical Technology, third edition,volume 14, pages 477-526.

[0013] A particular goal in the formulation of blends is the enhancementof viscosity index by the addition of VI improvers which are typicallyhigh molecular weight synthetic organic molecules. Such additives arecommonly produced from polyisobutylenes, polymethacrylates andpolyalkylstyrenes, and used in the molecular weight range of about45,000 to about 1,700,000. While effective in improving viscosity index,these VI improvers have been found to be deficient because the veryproperty of high molecular weight that makes them useful as VI improversalso confers upon the blend a vulnerability in shear stability duringactual applications. Temporary shear results from the non-Newtonianviscometrics associated with solutions of high molecular weight polymersand is caused by an alignment of the polymer chains with the shear fieldunder high shear rates with a resultant decrease in viscosity. Thedecreased viscosity reduces the wear protection associated with viscousoils. (Newtonian fluids, in contrast, maintain their viscosityregardless of shear rate.) This deficiency in shear stabilitydramatically reduces the range of useful applications for many VIimprover additives. Accordingly, workers in the lubricant arts continueto search for better lubricant blends with high viscosity indices.

[0014] Current market conditions are extremely favorable for lubricantcompositions which provide lower operating temperatures, increasedoperating efficiency, and increased hardware durability. With the adventof longer axle and transmission oil change intervals (ca 250,000 to500,000 miles), durability is clearly at issue as well. Accordingly, thepresent invention meets these needs by allowing for the preparation ofmultigraded automotive gear lubricants, and lubricating fluids, whichout perform prior art formulations and have none, or a greatly decreasedamount of, the deficiencies found in the currently commerciallyavailable lubricants.

SUMMARY OF THE INVENTION

[0015] The present invention comprises novel lubricating compositions,automotive gear lubricating compositions, and fluids useful in thepreparation of finished automotive gear lubricants. The novellubricating compositions of the present invention comprise a highviscosity fluid blended with a lower viscosity fluid, wherein the finalblend has a viscosity index greater than or equal to 175. In anotherembodiment, the novel lubricating compositions of the present inventioncomprise a major amount of a blend of a high viscosity fluid blendedwith a lower viscosity fluid, wherein the final blend has a viscosityindex greater than or equal to 175. The blend of the high viscosityfluid and the lower viscosity fluid is generally in a major amount whenpresent in an amount about 70 wt. % or greater by weight of the totalcomposition, preferably about 90% or greater by weight of the totalcomposition. Preferably, the high viscosity fluid comprises apolyalphaolefin and/or the lower viscosity fluid comprises a synthetichydrocarbon. In another embodiment, the novel lubricating compositionsof the present invention further comprise one or more of an ester,mineral oil and/or hydroprocessed mineral oil.

[0016] In another embodiment, the novel lubricating compositions of thepresent invention comprise finished gear oil.

[0017] In another embodiment, the present invention comprises a methodof preparing lubricating compositions, having the properties discussedherein, comprising blending a high viscosity fluid with a lowerviscosity fluid, wherein the final blend has a viscosity index greaterthan or equal to 175. The method may also further comprise the additionof one or more of an ester, mineral oil and/or hydroprocessed mineraloil, optionally in the percentages by weight discussed herein.

[0018] In another embodiment, the novel lubricating compositions of thepresent invention comprise: a high viscosity fluid, said high viscosityfluid having a viscosity of greater than or equal to 40 cSt. at 100° C.and less than or equal to 3,000 cSt. at 100° C., blended with a lowerviscosity fluid, said lower viscosity fluid having a viscosity of lessthan or equal to 40 cSt. at 100° C., wherein the final blend of saidhigh viscosity fluid and said lower viscosity fluid has a viscosityindex greater than or equal to 175.

[0019] In another embodiment, the present invention comprises anautomotive gear lubricating composition comprising: a high viscosityfluid, said high viscosity fluid having a viscosity of greater than orequal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt. at 100°C., blended with a lower viscosity fluid, said lower viscosity fluidhaving a viscosity of less than or equal to 40 cSt. at 100° C., whereinthe final blend of said high viscosity fluid and said lower viscosityfluid has a viscosity index greater than or equal to 175.

[0020] In another embodiment, the present invention comprises anautomotive gear lubricating composition comprising a blend of components(A) and (B), wherein: component (A) comprises a high viscosity fluid,said high viscosity fluid having (i) a viscosity of greater than orequal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt. at 100°C. and, (ii) a viscosity index greater than or equal to 180; andcomponent (B) comprises a lower viscosity fluid, said lower viscosityfluid having a viscosity of less than or equal to 40 cSt. at 100° C.;wherein the final blend of components (A) and (B) has a viscosity indexgreater than or equal to 175.

[0021] In another embodiment, the present invention comprises a methodof preparing a lubricating composition comprising blending a highviscosity fluid, said high viscosity fluid having a viscosity of greaterthan or equal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt.at 100° C., blended with a lower viscosity fluid, said lower viscosityfluid having a viscosity of less than or equal to 40 cSt. at 100° C.,wherein the final blend of said high viscosity fluid and said lowerviscosity fluid has a viscosity index greater than or equal to 175.

[0022] In another embodiment, the present invention comprises anautomotive gear lubricating composition comprising: a major amount of ablend of a high viscosity fluid blended with a lower viscosity fluid,said high viscosity fluid having a viscosity of greater than or equal to40 cSt. at 100° C. and less than or equal to 3,000 cSt. at 100° C., saidlower viscosity fluid having a viscosity of less than or equal to 40cSt. at 100° C., wherein the final blend of said high viscosity fluidand said lower viscosity fluid has a viscosity index greater than orequal to 175.

[0023] In another embodiment, the present invention comprises anautomotive gear lubricating composition comprising: a high viscosityfluid, said high viscosity fluid having a viscosity of greater than orequal to 80 cSt. at 100° C. and less than or equal to 300 cSt. at 100°C., blended with a lower viscosity fluid, said lower viscosity fluidhaving a viscosity of less than or equal to 6 cSt. at 100° C. andgreater than or equal to 1.5 cSt. at 100° C., wherein the final blend ofsaid high viscosity fluid and said lower viscosity fluid has a viscosityindex greater than or equal to 190.

BRIEF DESCRIPTION OF THE FIGURES

[0024]FIG. 1 presents graphically test results in accordance withembodiments of the present invention relative to currently availablecommercial gear oils.

[0025]FIG. 2 presents graphically test results in accordance withembodiments of the present invention relative to currently availablecommercial gear oils.

DESCRIPTION OF THE INVENTION

[0026] The present invention comprises novel lubricating compositionsuseful in the preparation of finished gear lubricants and automotivegear lubricants. The novel lubricating compositions of the presentinvention comprise a high viscosity fluid blended with a lower viscosityfluid, wherein the final blend of the high viscosity fluid and the lowerviscosity fluid has a viscosity index greater than or equal to 175. Inanother embodiment, the novel lubricating compositions of the presentinvention comprise a major amount of a blend of a high viscosity fluidblended with a lower viscosity fluid, wherein the final blend of saidhigh viscosity fluid and said lower viscosity fluid has a viscosityindex greater than or equal to 175. (The blend of the high viscosityfluid and the lower viscosity fluid is generally in a major amount whenpresent in an amount about 70% or greater by weight of the totalcomposition, preferably about 90% or greater by weight of the totalcomposition.) Compositions of the present invention exhibit very highstability to permanent shear and, because of their Newtonian nature,very little, if any, temporary shear thereby maintaining the viscosityrequired for proper wear protection.

[0027] In another embodiment, the novel lubricating compositions of thepresent invention comprise: a high viscosity fluid, said high viscosityfluid having a viscosity of greater than or equal to 40 cSt. at 100° C.and less than or equal to 3,000 cSt. at 100° C., blended with a lowerviscosity fluid, said lower viscosity fluid having a viscosity of lessthan or equal to 40 cSt. at 100° C., wherein the final blend of saidhigh viscosity fluid and said lower viscosity fluid has a viscosityindex greater than or equal to 175.

[0028] In another embodiment of the novel lubricating compositions ofthe present invention, the high viscosity fluid has a viscosity ofgreater than or equal to 60 cSt. at 100° C. In another embodiment of thenovel lubricating compositions of the present invention, the highviscosity fluid has a viscosity of less than or equal to 1,000 cSt. at100° C. In another embodiment of the novel lubricating compositions ofthe present invention, the high viscosity fluid has a viscosity ofgreater than or equal to 60 cSt. at 100° C. and less than or equal to1,000 cSt. at 100° C.

[0029] In another embodiment of the novel lubricating compositions ofthe present invention, the high viscosity fluid has a viscosity ofgreater than or equal to 80 cSt. at 100° C. In another embodiment of thenovel lubricating compositions of the present invention, the highviscosity fluid has a viscosity of less than or equal to 300 cSt. at100° C. In another embodiment of the novel lubricating compositions ofthe present invention, the high viscosity fluid has a viscosity ofgreater than or equal to 80 cSt. at 100° C. and less than or equal to300 cSt. at 100° C.

[0030] In another embodiment of the novel lubricating compositions ofthe present invention, the lower viscosity fluid has a viscosity of lessthan or equal to 10 cSt. at 100° C. In another embodiment of the novellubricating compositions of the present invention, the lower viscosityfluid has a viscosity of less than or equal to 6 cSt. at 100° C. Inanother embodiment of the novel lubricating compositions of the presentinvention, the lower viscosity fluid has a viscosity of greater than orequal to 1.5 cSt. at 100° C. and less than or equal to 10 cSt. at 100°C. In another embodiment of the novel lubricating compositions of thepresent invention, the lower viscosity fluid has a viscosity of greaterthan or equal to 1.5 cSt. at 100° C. and less than or equal to 6 cSt. at100° C.

[0031] In another embodiment of the novel lubricating compositions ofthe present invention, the viscosity index of the final blend of thehigh viscosity fluid and the lower viscosity fluid is greater than orequal to 190.

[0032] In another embodiment of the novel lubricating compositions ofthe present invention, the high viscosity fluid and the lower viscosityfluid comprise base stocks.

[0033] In another embodiment, the novel lubricating compositions of thepresent invention further comprise an ester. In another embodiment ofthe novel lubricating compositions of the present invention, the highviscosity fluid comprises a polyalphaolefin. In another embodiment ofthe novel lubricating compositions of the present invention, the highviscosity fluid and the lower viscosity fluid comprise polyalphaolefins.In another embodiment of the novel lubricating compositions of thepresent invention, the lower viscosity fluid comprises a synthetichydrocarbon. In another embodiment, the novel lubricating compositionsof the present invention further comprise one or more of an ester,mineral oil and/or hydroprocessed mineral oil.

[0034] In another embodiment of the novel lubricating compositions ofthe present invention, the high viscosity fluid comprises apolyalphaolefin in an amount of from about 30% to about 60% by weight ofthe total composition. In another embodiment of the novel lubricatingcompositions of the present invention, the lower viscosity fluidcomprises 0% to about 70% by weight of the total composition of asynthetic hydrocarbon. In another embodiment, the novel lubricatingcompositions of the present invention further comprise 0% to about 20%by weight of the total composition of an ester. In another embodiment,the novel lubricating compositions of the present invention furthercomprise 0% to about 20% by weight of the total composition of one ormore of an ester, mineral oil and/or hydroprocessed mineral oil.

[0035] In another embodiment, the novel lubricating compositions of thepresent invention further comprise one or more of: thickeners,antioxidants, inhibitor packages, and/or anti-rust additives; and/orfurther comprise one or more of: dispersants, detergents, frictionmodifiers, traction improving additives, demulsifiers, defoamants,chromophores (dyes), and/or haze inhibitors.

[0036] In another embodiment, the novel lubricating compositions of thepresent invention, comprise a finished gear oil. In another embodimentof the finished gear oil of the present invention, the blend of the highviscosity fluid blended with the lower viscosity fluid comprises a majoramount of said finished gear oil.

[0037] In another embodiment, the novel lubricating compositions of thepresent invention further comprise extreme pressure protection andanti-wear additives.

[0038] In another embodiment, the novel lubricating compositions of thepresent invention comprises an automatic transmission fluid, manualtransmission fluid, transaxle lubricant, gear lubricant, open gearlubricant, enclosed gear lubricant, and/or tractor lubricant.

[0039] In another embodiment, the novel lubricating compositions of thepresent invention comprises a contact surface comprising at least aportion of an automatic transmission, manual transmission, transaxle,gear, open gear, enclosed gear, and/or tractor.

[0040] In another embodiment, the present invention comprises anautomotive gear lubricating composition comprising: a high viscosityfluid, said high viscosity fluid having a viscosity of greater than orequal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt. at 100°C., blended with a lower viscosity fluid, said lower viscosity fluidhaving a viscosity of less than or equal to 40 cSt. at 100° C., whereinthe final blend of said high viscosity fluid and said lower viscosityfluid has a viscosity index greater than or equal to 175.

[0041] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, the high viscosity fluid has aviscosity of greater than or equal to 60 cSt. at 100° C. In anotherembodiment of the novel automotive gear lubricating compositions of thepresent invention, the high viscosity fluid has a viscosity of less thanor equal to 1,000 cSt. at 100° C. In another embodiment of the novelautomotive gear lubricating compositions of the present invention, thehigh viscosity fluid has a viscosity of greater than or equal to 60 cSt.at 100° C. and less than or equal to 1,000 cSt. at 100° C.

[0042] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, the high viscosity fluid has aviscosity of greater than or equal to 80 cSt. at 100° C. In anotherembodiment of the novel automotive gear lubricating compositions of thepresent invention, the high viscosity fluid has a viscosity of less thanor equal to 300 cSt. at 100° C. In another embodiment of the novelautomotive gear lubricating compositions of the present invention, thehigh viscosity fluid has a viscosity of greater than or equal to 80 cSt.at 100° C. and less than or equal to 300 cSt. at 100° C.

[0043] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, the lower viscosity fluid has aviscosity of less than or equal to 10 cSt. at 100° C. In anotherembodiment of the novel automotive gear lubricating compositions of thepresent invention, the lower viscosity fluid has a viscosity of lessthan or equal to 6 cSt. at 100° C. In another embodiment of the novelautomotive gear lubricating compositions of the present invention, thelower viscosity fluid has a viscosity of greater than or equal to 1.5cSt. at 100° C. and less than or equal to 10 cSt. at 100° C. In anotherembodiment of the novel automotive gear lubricating compositions of thepresent invention, the lower viscosity fluid has a viscosity of greaterthan or equal to 1.5 cSt. at 100° C. and less than or equal to 6 cSt. at100° C.

[0044] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, the viscosity index of the finalblend of the high viscosity fluid and the lower viscosity fluid isgreater than or equal to 190. In another embodiment of the novelautomotive gear lubricating compositions of the present invention, thehigh viscosity fluid and the lower viscosity fluid comprise base stocks.

[0045] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention further comprise an ester. Inanother embodiment of the novel automotive gear lubricating compositionsof the present invention, the high viscosity fluid comprises apolyalphaolefin. In another embodiment of the novel automotive gearlubricating compositions of the present invention, the high viscosityfluid and the lower viscosity fluid comprise polyalphaolefins. Inanother embodiment of the novel automotive gear lubricating compositionsof the present invention, the lower viscosity fluid comprises asynthetic hydrocarbon. In another embodiment, the novel automotive gearlubricating compositions of the present invention further comprise oneor more of an ester, mineral oil and/or hydroprocessed mineral oil.

[0046] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, the high viscosity fluidcomprises a polyalphaolefin in an amount of from about 30% to about 60%by weight of the total composition. In another embodiment of the novelautomotive gear lubricating compositions of the present invention, thelower viscosity fluid comprises 0% to about 70% by weight of the totalcomposition of a synthetic hydrocarbon. In another embodiment, the novelautomotive gear lubricating compositions of the present inventionfurther comprise 0% to about 20% by weight of the total composition ofan ester. In another embodiment, the novel automotive gear lubricatingcompositions of the present invention further comprise 0% to about 20%by weight of the total composition of one or more of an ester, mineraloil and/or hydroprocessed mineral oil.

[0047] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention further comprise one or more of:thickeners, antioxidants, inhibitor packages, and/or anti-rustadditives; and/or further comprise one or more of: dispersants,detergents, friction modifiers, traction improving additives,demulsifiers, defoamants, chromophores (dyes), and/or haze inhibitors.

[0048] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention comprise a finished gear oil. Inanother embodiment, of said finished gear oil of the present inventionthe blend of the high viscosity fluid blended with the lower viscosityfluid comprises a major amount of said finished gear oil.

[0049] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention further comprise extreme pressureprotection and anti-wear additives.

[0050] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention comprises an automatictransmission fluid, manual transmission fluid, transaxle lubricant, gearlubricant, open gear lubricant, enclosed gear lubricant, and/or tractorlubricant.

[0051] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention comprises a contact surfacecomprising at least a portion of an automatic transmission, manualtransmission, transaxle, gear, open gear, enclosed gear, and/or tractor.

[0052] In another embodiment, the present invention comprises anautomotive gear lubricating composition comprising a blend of components(A) and (B), wherein: component (A) comprises a high viscosity fluid,said high viscosity fluid having (i) a viscosity of greater than orequal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt. at 100°C. and, (ii) a viscosity index greater than or equal to 180; andcomponent (B) comprises a lower viscosity fluid, said lower viscosityfluid having a viscosity of less than or equal to 40 cSt. at 100° C.;wherein the final blend of components (A) and (B) has a viscosity indexgreater than or equal to 175.

[0053] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, the final blend of components (A)and (B) has a viscosity index greater than or equal to 190.

[0054] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, the viscosity index of component(A) is greater than or equal to 190.

[0055] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, component (A) and component (B)comprise base stocks.

[0056] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention further comprise an ester. Inanother embodiment, the novel automotive gear lubricating compositionsof the present invention further comprise 0% to about 20% by weight ofthe total composition of an ester.

[0057] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, component (A) comprises apolyalphaolefin.

[0058] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, components (A) and (B) comprisepolyalphaolefins.

[0059] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention further comprise one or more of anester, mineral oil and/or hydroprocessed mineral oil. In anotherembodiment, the novel automotive gear lubricating compositions of thepresent invention further comprise 0% to about 20% by weight of thetotal composition of one or more of an ester, mineral oil and/orhydroprocessed mineral oil.

[0060] In another embodiment of the novel automotive gear lubricatingcompositions of the present invention, component (A) comprises apolyalphaolefin in an amount of from about 30% to about 60% by weight ofthe total composition.

[0061] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention further comprise one or more of:thickeners, antioxidants, inhibitor packages, and/or anti-rustadditives; and/or further comprise one or more of: dispersants,detergents, friction modifiers, traction improving additives,demulsifiers, defoamants, chromophores (dyes), and/or haze inhibitors.

[0062] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention comprise a finished gear oil.

[0063] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention further comprise extreme pressureprotection and anti-wear additives.

[0064] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention comprises an automatictransmission fluid, manual transmission fluid, transaxle lubricant, gearlubricant, open gear lubricant, enclosed gear lubricant, and/or tractorlubricant.

[0065] In another embodiment, the novel automotive gear lubricatingcompositions of the present invention comprise a contact surfacecomprising at least a portion of an automatic transmission, manualtransmission, transaxle, gear, open gear, enclosed gear, and/or tractor.

[0066] In another embodiment, the present invention comprises a methodof preparing a lubricating composition comprising blending a highviscosity fluid, said high viscosity fluid having a viscosity of greaterthan or equal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt.at 100° C., with a lower viscosity fluid, said lower viscosity fluidhaving a viscosity of less than or equal to 40 cSt. at 100° C., whereinthe final blend of said high viscosity fluid and said lower viscosityfluid has a viscosity index greater than or equal to 175.

[0067] In another embodiment of the method of preparing a lubricatingcomposition of the present invention, the high viscosity fluid has aviscosity index of 180 or greater.

[0068] In another embodiment of the method of preparing a lubricatingcomposition of the present invention, the final blend of said highviscosity fluid and said lower viscosity fluid has a viscosity indexgreater than or equal to 190.

[0069] In another embodiment of the method of preparing a lubricatingcomposition of the present invention, the high viscosity fluid and thelower viscosity fluid comprise base stocks.

[0070] In another embodiment of the method of preparing a lubricatingcomposition of the present invention, the blend of the high viscosityfluid blended with the lower viscosity fluid comprises a major amount ofthe lubricating composition.

[0071] In another embodiment of the method of preparing a lubricatingcomposition of the present invention, the high viscosity fluid comprisesa polyalphaolefin.

[0072] In another embodiment of the method of preparing a lubricatingcomposition of the present invention, the lower viscosity fluidcomprises a synthetic hydrocarbon.

[0073] In another embodiment, the method of preparing a lubricatingcomposition of the present invention further comprises the step ofadding 0% to about 20% by weight of the total composition of an ester.

[0074] In another embodiment, the method of preparing a lubricatingcomposition of the present invention further comprises the step ofadding 0% to about 20% by weight of the total composition of one or moreof an ester, mineral oil and/or hydroprocessed mineral oil.

[0075] In another embodiment, the method of preparing a lubricatingcomposition of the present invention further comprises the step ofadding one or more of: thickeners, antioxidants, inhibitor packages,and/or anti-rust additives; and/or further comprises the step of addingone or more of: dispersants, detergents, friction modifiers, tractionimproving additives, demulsifiers, defoamants, chromophores (dyes),and/or haze inhibitors.

[0076] In another embodiment, the method of preparing a lubricatingcomposition of the present invention further comprises the step ofadding extreme pressure protection and anti-wear additives.

[0077] In another embodiment, the product of the method of preparing alubricating composition of the present invention comprises an automatictransmission fluid, manual transmission fluid, transaxle lubricant, gearlubricant, open gear lubricant, enclosed gear lubricant, and/or tractorlubricant.

[0078] In another embodiment, the product of the method of preparing alubricating composition of the present invention comprises a contactsurface comprising at least a portion of an automatic transmission,manual transmission, transaxle, gear, open gear, enclosed gear, and/ortractor.

[0079] In another embodiment, the present invention comprises theproduct of the aforementioned method of preparing a lubricatingcomposition.

[0080] In another embodiment, the present invention comprises anautomotive gear lubricating composition comprising: a major amount of ablend of a high viscosity fluid blended with a lower viscosity fluid,said high viscosity fluid having a viscosity of greater than or equal to40 cSt. at 100° C. and less than or equal to 3,000 cSt. at 100° C., saidlower viscosity fluid having a viscosity of less than or equal to 40cSt. at 100° C., wherein the final blend of said high viscosity fluidand said lower viscosity fluid has a viscosity index greater than orequal to 175.

[0081] In another embodiment of the novel automotive gear lubricatingcomposition of the present invention comprising a major amount of ablend of a high viscosity fluid blended with a lower viscosity fluid,said high viscosity fluid and said lower viscosity fluid comprise basestocks.

[0082] In another embodiment, the present invention comprises anautomotive gear lubricating composition comprising: a high viscosityfluid, said high viscosity fluid having a viscosity of greater than orequal to 80 cSt. at 100° C. and less than or equal to 300 cSt. at 100°C., blended with a lower viscosity fluid, said lower viscosity fluidhaving a viscosity of less than or equal to 6 cSt. at 100° C. andgreater than or equal to 1.5 cSt. at 100° C., wherein the final blend ofsaid high viscosity fluid and said lower viscosity fluid has a viscosityindex greater than or equal to 190.

[0083] A preferred embodiment of the present invention comprises a highviscosity fluid, said high viscosity fluid having a viscosity of greaterthan or equal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt.at 100° C., more preferably greater than or equal to 60 cSt. at 100° C.and less than or equal to 1,000 cSt. at 100° C., most preferably greaterthan or equal to 80 cSt. at 100° C. and less than or equal to 300 cSt.at 100° C., blended with a lower viscosity fluid, the lower viscosityfluid having a viscosity of less than or equal to 40 cSt. at 100° C.,more preferably less than or equal to 10 cSt. at 100° C. and greaterthan or equal to 1.5 cSt. at 100° C., most preferably less than or equalto 6 cSt. at 100° C. and greater than or equal to 1.5 cSt. at 100° C.,wherein the final blend of the high viscosity fluid and the lowerviscosity fluid has a viscosity index greater than or equal to 175, morepreferably greater than or equal to 190.

[0084] In a preferred embodiment according to the present invention, thenovel automotive gear lubricating compositions comprise: (i) a majoramount of a blend (about 70% or greater by weight of the totalcomposition, preferably about 90% or greater) of a high viscosity fluid,said high viscosity fluid having a viscosity of greater than or equal to40 cSt. at 100° C. and less than or equal to 3,000 cSt. at 100° C.,blended with a lower viscosity fluid, said lower viscosity fluid havinga viscosity of less than or equal to 40 cSt. at 100° C., wherein thefinal blend of the high viscosity fluid and the lower viscosity fluidhas a viscosity index greater than or equal to 175, more preferablygreater than or equal to 190; and (ii) a minor amount of extremepressure protection and anti-wear additives.

[0085] Fluids

[0086] High viscosity fluids suitable for the present invention arefluids having a viscosity of greater than or equal to 40 cSt. at 100° C.and less than or equal to 3,000 cSt. at 100° C., preferably greater thanor equal to 60 cSt. at 100° C. and less than or equal to 1,000 cSt. at100° C., more preferably greater than or equal to 80 cSt. at 100° C. andless than or equal to 300 cSt. at 100° C. Lower viscosity fluidssuitable for the present invention are fluids having a viscosity of lessthan or equal to 40 cSt. at 100° C., preferably less than or equal to 10cSt. at 100° C. and greater than or equal to 1.5 cSt. at 100° C., morepreferably less than or equal to 6 cSt. at 100° C. and greater than orequal to 1.5 cSt. at 100° C. Examples of suitable high viscosity andlower viscosity fluids are discussed hereafter.

[0087] Lower viscosity fluids suitable for the present invention may besynthetic, or of mineral oil, origin although the synthetic materialsare preferred. Suitable mineral oil stocks are characterized by apredominantly saturated (paraffinic) composition, relative freedom fromsulfur and a high viscosity index (ASTM D 2270), greater than 110.Saturates (ASTM D 2007) are at least 90 weight percent and thecontrolled sulfur content is not more than 0.03 weight percent (ASTM D2622, D 4294, D 4927, D 3120). Lower viscosity fluids of mineral oilorigin include the hydroprocessed stocks, especially hydrotreated andcatalytically hydrodewaxed distillate stocks, catalytically hydrodewaxedraffinates, hydrocracked and hydroisomerized petroleum waxes, includingthe lubricating oils referred to as XHVI oils, as well as other oils ofmineral origin generally classified as API Group III base stocks.Exemplary streams of mineral origin which may be converted into suitablehigh quality base stocks by hydroprocessing techniques include waxydistillate stocks such as gas oils, slack waxes, deoiled waxes andmicrocrystalline waxes, and fuels hydrocracker bottoms fractions.Processes for the hydroisomerization of petroleum waxes and other feedsto produce high quality lube stocks are described in U.S. Pat. Nos.5,885,438; 5,643,440; 5,358,628; 5,302,279; 5,288,395; 5,275,719;5,264,116 and 5,110,445. The production of very high-quality lubricantbase stocks of high viscosity index from fuels hydrocracker bottoms isdescribed in U.S. Pat. No. 5,468,368.

[0088] Preferred Group V hydrocarbon components suitable for the presentinvention also include the oils of lubricating viscosity which arehydrocarbon substituted aromatic compounds, such as the long chain alkylsubstituted aromatics, including the alkylated naphthalenes, alkylatedbenzenes, alkylated diphenyl compounds and alkylated diphenyl methanes.

[0089] Synthetic Hydrocarbons

[0090] Synthetic lower viscosity fluids suitable for the presentinvention include the polyalphaolefins (PAOs) and the synthetic oilsfrom the hydrocracking or hydroisomerization of Fischer Tropsch highboiling fractions including waxes. These are both stocks comprised ofsaturates with low impurity levels consistent with their syntheticorigin. The hydroisomerized Fischer Tropsch waxes are highly suitablebase stocks, comprising saturated components of iso-paraffinic character(resulting from the isomerization of the predominantly n-paraffins ofthe Fischer Tropsch waxes) which give a good blend of high viscosityindex and low pour point. Processes for the hydroisomerization ofFischer Tropsch waxes are described in U.S. Pat. Nos. 5,362,378;5,565,086; 5,246,566 and 5,135,638, as well as in EP 710710, EP 321302and EP 321304.

[0091] Polyalphaolefins (“PAOs”)

[0092] Polyalphaolefins suitable for the present invention, as eitherlower viscosity or high viscosity fluids depending on their specificproperties, include known PAO materials which typically compriserelatively low molecular weight hydrogenated polymers or oligomers ofalphaolefins which include but are not limited to C₂ to about C₃₂alphaolefins with the C₈ to about C₁₆ alphaolefins, such as 1-octene,1-decene, 1-dodecene and the like being preferred. The preferredpolyalphaolefins are poly-1-octene, poly-1-decene, and poly-1-dodecene,although the dimers of higher olefins in the range of C₁₄ to C₁₈ providelow viscosity base stocks.

[0093] PAO fluids suitable for the present invention, as either lowerviscosity or high viscosity fluids depending on their specificproperties, may be conveniently made by the polymerization of analphaolefin in the presence of a polymerization catalyst such as theFriedel-Crafts catalysts including, for example, aluminum trichloride,boron trifluoride or complexes of boron trifluoride with water, alcoholssuch as ethanol, propanol or butanol, carboxylic acids or esters such asethyl acetate or ethyl propionate. For example, the methods disclosed byU.S. Pat. Nos. 4,149,178 or 3,382,291 may be conveniently used herein.Other descriptions of PAO synthesis are found in the following U.S. Pat.No. 3,742,082 (Brennan); U.S. Pat. No. 3,769,363 (Brennan); U.S. Pat.No. 3,876,720 (Heilman); U.S. Pat. No. 4,239,930 (Allphin); U.S. Pat.No. 4,367,352 (Watts); U.S. Pat. No. 4,413,156 (Watts); U.S. Pat. No.4,434,408 (Larkin); U.S. Pat. No. 4,910,355 (Shubkin); U.S. Pat. No.4,956,122 (Watts); and U.S. Pat. No. 5,068,487 (Theriot).

[0094] High viscosity PAOs suitable for the present invention may beprepared by the action of a reduced chromium catalyst with thealphaolefin, such PAOs are described in U.S. Pat. No. 4,827,073 (Wu);U.S. Pat. No. 4,827,064 (Wu); U.S. Pat. No. 4,967,032 (Ho et al.); U.S.Pat. No. 4,926,004 (Pelrine et al.); and, U.S. Pat. No. 4,914,254(Pelrine). The dimers of the C₁₄ to C₁₈ olefins are described in U.S.Pat. No. 4,218,330. Commercially available high viscosity PAOs includeSuperSyn™ 2150, SuperSyn™ 2300, SuperSyn™ 21000, SyperSyn™ 23000,(ExxonMobil Chemical Company).

[0095] Esters

[0096] Esters suitable for the present invention include the esters ofmono and polybasic acids with monoalkanols (simple esters) or withmixtures of mono and polyalkanols (complex esters), and the polyolesters of monocarboxylic acids (simple esters), or mixtures of mono andpolycarboxylic acids (complex esters). Esters of the mono/polybasic typeinclude, for example, the esters of monocarboxylic acids such asheptanoic acid, and dicarboxylic acids such as phthalic acid, succinicacid, alkyl succinic acid, alkenyl succinic acid, maleic acid, azelaicacid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleicacid dimer, malonic acid, alkyl malonic acid, alkenyl malonic acid,etc., with a variety of alcohols such as butyl alcohol, hexyl alcohol,dodecyl alcohol, 2-ethylhexyl alcohol, or mixtures thereof withpolyalkanols, etc. Specific examples of these types of esters includenonyl heptanoate, dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexylfumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate,dioctyl phthalate, didecyl phthalate, dieicosyl sebacate,dibutyl-TMP-adipate, etc. Commercially available examples includeEsterex™ M11, A32, A51 and C3211 esters from ExxonMobil ChemicalCompany.

[0097] Also suitable for the present invention are esters, such as thoseobtained by reacting one or more polyhydric alcohols, preferably thehindered polyols such as the neopentyl polyols, e.g. neopentyl glycol,trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylolpropane, trimethylol butane, pentaerythritol and dipentaerythritol withmonocarboxylic acids containing at least 4 carbons, normally the C₅ toC₃₀ acids such as saturated straight chain fatty acids includingcaprylic acid, capric acid, lauric acid, myristic acid, palmitic acid,stearic acid, arachic acid, and behenic acid, or the correspondingbranched chain fatty acids or unsaturated fatty acids such as oleicacid, or mixtures thereof, with polycarboxylic acids. Commerciallyavailable examples include Esterex™ NP341, NP471, and NP3150 esters fromExxonMobil Chemical Company.

[0098] Extreme Pressure Protection and Anti-Wear Additives

[0099] In another embodiment, the novel lubricating compositions of thepresent invention further comprise extreme pressure protection andanti-wear additives. For example, mixtures of sulfur, phosphorus and/orboron-containing compounds may be included as additives, such asmixtures of Mobilad™ C-100, Mobilad™ C-175 (sulfur); Mobilad™ C-420,Mobilad™ C-421, Mobilad™ C-423 (phosphorus); and/or Mobilad™ C-200(boron) (ExxonMobil Chemical Company). Lubricants containing thesecombinations have improved properties such as those relating to odor,yellow metal protection, thermal stability wear, scuffing, oxidation,surface fatigue, seal compatibility, corrosion resistance, and thermaldurability. Other extreme pressure protection and anti-wear additivesknown in the art may also be used.

[0100] Other Components

[0101] Other components which may be included in the novel lubricatingcompositions of the present invention include, but are not limited to,thickeners, antioxidants, inhibitor packages and/or anti-rust additives.Additionally, other conventional additives may be included in the novelcompositions of the present invention as necessary for particularservice requirements, for example, dispersants, detergents, frictionmodifiers, traction improving additives, demulsifiers, defoamants,chromophores (dyes), and/or haze inhibitors, according to application,all of which may be blended according to conventional methods usingcommercially available materials.

[0102] The viscosity of the lubricating compositions of the presentinvention may be brought to a desired grade by the use of polymericthickeners. Suitable thickeners that may be used in the presentinvention include the polyisobutylenes, as well as ethylene-propylenepolymers, polymethacrylates and various diene block polymers andcopolymers, polyolefins and polyalkylstyrenes. These components may beblended according to commercial market requirement, equipment builderspecifications to produce products of the final desired viscosity grade.

[0103] Typical commercially available thickeners also appropriate foruse in lubricating compositions of the present invention includepolyisobutylenes, polymerized and co-polymerized alkyl methacrylates,and mixed esters of styrene maleic anhydride interpolymers reacted withnitrogen containing compounds, for example, the Shellvis™ products (inparticular, Shellvis™ 40, Shellvis™ 50, Shellvis™ 90, Shellvis™ 200,Shellvis™ 260 and Shellvis™ 300) by Infineum International Ltd.,Acryloid™ 1263 and 1265 by Rohm and Haas, Viscoplex™ 5151 and 5089 byRohm-GmbH, and Lubrizol™ 3702 and 3715 by Lubrizol Corp.

[0104] Oxidation stability may be enhanced in the lubricatingcompositions of the present invention by the use of antioxidants and forthis purpose a wide range of commercially available materials issuitable. The most common types of antioxidants suitable for use in thepresent invention are the phenolic antioxidants, the amine typeantioxidants, the alkyl aromatic sulfides, phosphorus compounds such asthe phosphites and phosphonic acid esters and the sulfur-phosphoruscompounds such as the dithiophosphates and other types such as thedialkyl dithiocarbamates, e.g., methylene bis(di-n-butyl)dithiocarbamate. They may be used individually by type or in combinationwith one another. Mixtures of different types of phenols or amines areparticularly useful. Normally, the total amount of antioxidant will notexceed 10% by weight of the total composition and preferably will beless, for example below 5% by weight of the total composition. Usually,from 0.5 to 2% by weight of the total composition of an antioxidant issuitable, although for certain applications more may be used if desired.

[0105] An inhibitor package may be used to provide the desired balanceof anti-wear and anti-rust/anti-corrosion properties in the lubricatingcompositions of the present invention. Suitable inhibitor packagesinclude those comprising a substituted benzotriazoleamine phosphateadduct and a tri-substituted phosphate, especially a triaryl phosphatesuch as cresyl diphenylphosphate, a known material which is commerciallyavailable. This component is typically present in minor amounts up to 5%by weight of the composition. Normally less than 3% by weight of thetotal composition (e.g., from 0.5 to 2%) is adequate to provide thedesired anti-wear performance.

[0106] Also suitable for use in the lubricating compositions of thepresent invention are inhibitor packages comprising an adduct ofbenzotriazole or a substituted benzotriazole with an amine phosphateadduct which also provides antiwear and antioxidation performance.Certain multifunctional adducts of this kind (with aromatic amines) aredescribed in U.S. Pat. No. 4,511,481 to which reference is made for adescription of these adducts together with the method by which they maybe prepared.

[0107] Anti-rust additives suitable for use in the present inventioninclude metal deactivators which are commercially available andtypically include, for example, the N,N-disubstitutedaminomethyl-1,2,4-triazoles, and the N,N-disubstituted aminomethyl-benzotriazoles, the succinimide derivatives such as the higheralkyl substituted amides of dodecylene succinic acid, which are alsocommercially available, the higher alkyl substituted amides of dodecenylsuccinic acid, such as the tetrapropenylsuccinic monoesters(commercially available), and imidazoline succinic anhydridederivatives, e.g., the imidazoline derivatives of tetrapropenyl succinicanhydride. Normally, these additional rust inhibitors will be used inrelatively small amounts below 2% by weight of the total composition;although for certain applications amounts up to about 5% may be employedif necessary.

EXAMPLES

[0108] The lubricating compositions of the present invention may beprepared using standard commercial lube oil blending facilitiesconsisting of blend tanks and/or inline mixers where heat is used onlyto facilitate pumping and complete mixing.

[0109] Examples A-H, hereafter, illustrate properties of embodiments offinished gear oils comprising the lubricating compositions of thepresent invention. The following tables, charts, and attached Figuressummarize the benefits that were observed for embodiments of the presentinvention.

Example A

[0110] SAE Viscosity Component Description Wt % Grade Additive Package AGear Oil Additive 6.00 SAE 70W-90 Package VI = 227 ExxonMobil Lowerviscosity 24.00 SHF ™ 23 hydrocarbon fluid ExxonMobil Lower viscosityester 20.00 Esterex ™ M11 ExxonMobil High viscosity 49.98 Supersyn ™2150 hydrocarbon fluid Silicon Defoamant Defoamant 0.02

Example B

[0111] SAE Viscosity Component Description Wt % Grade Additive Package AGear Oil Additive 11.55 SAE 70W-85 Package VI = 227 Additive Antioxidant0.50 Component A ExxonMobil Lower viscosity 30.43 SHF ™ 23 hydrocarbonfluid ExxonMobil Lower viscosity ester 15.00 Esterex ™ M11 ExxonMobilHigh viscosity 43.00 Supersyn ™ 2150 hydrocarbon fluid Silicon DefoamantDefoamant 0.02

Example C

[0112] SAE Viscosity Component Description Wt % Grade Additive Package AGear Oil Additive 5.21 SAE 75W-90 Package VI = 199 ExxonMobil Lowerviscosity 25.00 SHF ™ 23 hydrocarbon fluid ExxonMobil Lower viscosity21.00 SHF ™ 41 hydrocarbon fluid ExxonMobil High viscosity 48.77Supersyn ™ 2150 hydrocarbon fluid Silicon Defoamant Defoamant 0.02

Example D

[0113] SAE Viscosity Component Description Wt % Grade Additive Package AGear Oil Additive 6.00 SAE 70W-90 Package VI = 216 ExxonMobil Lowerviscosity 24.85 SHF ™ 23 hydrocarbon fluid ExxonMobil Lower viscosityester 21.00 Esterex ™ M11 ExxonMobil High viscosity 27.50 SHF ™ 1003hydrocarbon fluid ExxonMobil High viscosity 21.65 Supersyn ™ 2300hydrocarbon fluid

Example E

[0114] SAE Viscosity Component Description Wt % Grade Additive Package AGear Oil Additive 6.00 SAE 70W-90 Package VI = 217 ExxonMobil Lowerviscosity 28.13 SHF ™ 23 hydrocarbon fluid ExxonMobil Lower viscosityester 20.00 Esterex ™ M11 ExxonMobil High viscosity 36.70 SHF ™ 1003hydrocarbon fluid ExxonMobil High viscosity 9.17 Supersyn ™ 2300hydrocarbon fluid

Example F

[0115] SAE Viscosity Component Description Wt % Grade Additive Package AGear Oil Additive 6.00 SAE 75W-90 Package VI = 192 ExxonMobil Lowerviscosity 19.00 SHF ™ 23 hydrocarbon fluid ExxonMobil Lower viscosityester 20.00 Esterex ™ M11 ExxonMobil High viscosity 55.00 SHF ™ 1003hydrocarbon fluid

Example G

[0116] SAE Viscosity Component Description Wt % Grade Additive Package AGear Oil Additive 6.00 SAE 75W-90 Package VI = 190 Mobilad G205 ™Friction Modifier 2.00 ExxonMobil Lower viscosity 18.00 SHF ™ 23hydrocarbon fluid ExxonMobil Lower viscosity ester 20.00 Esterex ™ M11ExxonMobil High viscosity 55.00 SHF ™ 1003 hydrocarbon fluid SiliconDefoamant Defoamant 0.02

Example H

[0117] SAE Viscosity Component Description Wt % Grade Additive Package AGear Oil Additive 6.00 SAE 75W-90 Package VI = 210 Additive Anti-oxidant0.25 Comp A Alkylated aromatic Lower viscosity 10.00 API Group Vhydrocarbon fluid (4.8 cSt. at 100° C.) ExxonMobil Lower viscosity 25.80SHF ™ 23 hydrocarbon fluid ExxonMobil Lower viscosity ester 10.00Esterex ™ M11 ExxonMobil High viscosity 47.93 Supersyn ™ 2150hydrocarbon fluid Silicon Defoamant Defoamant 0.02

[0118] Testing

[0119] Finished gear oils comprising the lubricating compositions of thepresent invention possess previously unseen benefits with respect tovehicle fuel economy and hardware durability and demonstratesignificantly enhanced lubricant performance. For instance, whenfinished gear oils comprising the lubricating compositions of thepresent invention are tested in truck axles, resultant oil sumptemperatures are lower than with current commercially availablelubricant fluids across a wide range of operating conditions. Theselowered axle sump temperatures are a consequence of reduced frictionwithin the drive train. The reduced friction leads directly toefficiency improvements. The lowered sump temperatures have the effectof enhancing hardware durability. Thus, the lubricant temperaturereduction seen in the finished gear oils comprising the lubricatingcompositions of the present invention yields increased fuel efficiencyand hardware durability.

[0120] The performance enhancements of the finished gear oils comprisingthe lubricating compositions of the present invention can bedemonstrated using automotive drive axles on laboratory test standswhere defined loads are applied to the test axles at constant axlespeeds and constant cooling. The test stages are defined to include therange of actual commercial operating conditions of load and speed. Oilsump temperatures can then be measured to demonstrate indirectly theimproved efficiency and hardware durability protection in the field.Alternately, the test stand can be instrumented with torque meters toestimate efficiencies more explicitly.

[0121] One such test uses a light truck axle mounted in a “T-bar” typetest configuration similar to ASTM D 6121-01(the L-37 gear durabilitytest), with the exception that in this test, the power source is from a250 hp electric motor and constant heat removal is provided by air fansdirected at the axle carrier. The axle carrier is filled with test oiland then run through stages of torques and rpms. Each stage is helduntil the oil sump temperature has stabilized. The temperature of eachstage is recorded along with torque in and torque out readings if theaxle is properly instrumented. The test then moves to the next stageuntil all stages are completed. Table 1 lists the torque and axle speedsthat was used to generate the test data described herein. TABLE 1 TorqueStage (lbf · ft.) RPM Comments 1 50 2000 A combination of torque andspeed predictive of typical low load applications 2 70 2000 Acombination of torque and speed predictive of typical low loadapplications 3 95 2000 A combination of torque and speed predictive oftypical low load applications 4 189 1000 A combination of torque andspeed predictive of middle load applications 5 418  500 A combination oftorque and speed predictive of high load applications 6 124 2700 Acombination of torque and speed predictive of middle load applications 7189 2730 A combination of torque and speed predictive of middle loadapplications 8 242 2730 A combination of torque and speed predictive ofmiddle load applications 9 304 2200 A combination of torque and speedpredictive of high load applications 10 418 1000 A combination of torqueand speed predictive of high load applications

[0122] In order to more clearly see relative sump temperatureimprovements, the resultant temperature at each stage is comparedrelative to currently available commercial gear oils and the datadisplayed as such in FIG. 1.

[0123] In FIG. 1, the two commercially available SAE 75W-90 factory filloils (FF#1 and FF#2) show indirectly the efficiency improvements in teststages 1-3 relative to the 75W-140 reference oil (normalized as shown onthe horizontal axis). Significant sump temperature increases relative tothe reference at high load stages 5, 9, and 10, however, indicatepossible film thickness loss and subsequent long-term hardwarecompromise. Examples A and B of the present invention in contrast showeven more striking temperature improvements at the low stages whilemaintaining fluid film thickness and therefore hardware protection atthe high load stages.

[0124]FIG. 2 further demonstrates results for additional embodiments ofthe present invention.

[0125] Consolidating the test information presented in FIGS. 1 and 2from the ten stages into three groups and averaging sump temperatureimprovements further focuses the benefits imparted by the compositionsof the present invention. Table 2 shows the stage consolidation andTable 3 summarizes the test results shown in FIGS. 1 and 2. TABLE 2Consolidation of Stages into Groups Group Stages ID Discussion used AMild test conditions typical of EPA focus for 1, 2, 3 vehicle mileagedocumentation B Increased hardware stress conditions, yet still 4, 6, 7,8 well within equipment design C High stress conditions close to orbeyond hardware 5, 9, 10 design envelope

[0126] TABLE 3 Relative Sump Temperature Averages, (° F.) Oil TestedGroup A Group B Group C OEM Reference 75W-140 0 0 0 (0 by definition)OEM FF 75W-90#1 −3 2 18 OEM FF 75W-90#2 −7 2 31 Example A −16 −18 3Example B −18 −17 6 Example D −14 −13 0 Example E −19 −16 9

[0127] In conclusion, the aforementioned examples of finished gear oilscomprising the lubricating compositions of the present inventiondemonstrate sump temperature improvements over both the reference andother commercial fluids with little or no durability compromise.

[0128] While certain representative embodiments and details have beenshown for purposes of illustrating the invention, it should berecognized that these embodiments are merely illustrative of theprinciples of the present invention. Since numerous modifications andchanges will readily occur to those skilled in the art, the foregoing isnot intended to limit the invention to the exact construction andoperation shown and described, and all suitable modifications andequivalents falling within the scope of the appended claims are deemedwithin the present inventive concept.

[0129] The features of the present invention, together with the otherobjectives of the invention, and along with the various features ofnovelty which characterize the invention, are pointed out withparticularity in the claims annexed to and forming a part of thisdisclosure.

We claim:
 1. A lubricating composition comprising: a high viscosityfluid, said high viscosity fluid having a viscosity of greater than orequal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt. at 100°C., blended with a lower viscosity fluid, said lower viscosity fluidhaving a viscosity of less than or equal to 40 cSt. at 100° C., whereinthe final blend of said high viscosity fluid and said lower viscosityfluid has a viscosity index greater than or equal to
 175. 2. Thelubricating composition of claim 1, wherein said high viscosity fluidhas a viscosity of greater than or equal to 60 cSt. at 100° C.
 3. Thelubricating composition of claim 1, wherein said high viscosity fluidhas a viscosity of less than or equal to 1,000 cSt. at 100° C.
 4. Thelubricating composition of claim 2, wherein said high viscosity fluidhas a viscosity of less than or equal to 1,000 cSt. at 100° C.
 5. Thelubricating composition of claim 1, wherein said high viscosity fluidhas a viscosity of greater than or equal to 80 cSt. at 100° C.
 6. Thelubricating composition of claim 1, wherein said high viscosity fluidhas a viscosity of less than or equal to 300 cSt. at 100° C.
 7. Thelubricating composition of claim 5, wherein said high viscosity fluidhas a viscosity of less than or equal to 300 cSt. at 100° C.
 8. Thelubricating composition of claim 1, wherein said lower viscosity fluidhas a viscosity of less than or equal to 10 cSt. at 100° C.
 9. Thelubricating composition of claim 1, wherein said lower viscosity fluidhas a viscosity of less than or equal to 6 cSt. at 100° C.
 10. Thelubricating composition of claim 8, wherein said lower viscosity fluidhas a viscosity of greater than or equal to 1.5 cSt. at 100° C.
 11. Thelubricating composition of claim 9, wherein said lower viscosity fluidhas a viscosity of greater than or equal to 1.5 cSt. at 100° C.
 12. Thelubricating composition of claim 1, wherein said viscosity index isgreater than or equal to
 190. 13. The lubricating composition of claim1, wherein said high viscosity fluid and said lower viscosity fluidcomprise base stocks.
 14. The lubricating composition of claim 1,further comprising an ester.
 15. The lubricating composition of claim 1,wherein said high viscosity fluid comprises a polyalphaolefin.
 16. Thelubricating composition of claim 1, wherein said high viscosity fluidand said lower viscosity fluid comprise polyalphaolefins.
 17. Thelubricating composition of claim 1, wherein said lower viscosity fluidcomprises a synthetic hydrocarbon.
 18. The lubricating composition ofclaim 1, further comprising one or more of an ester, mineral oil and/orhydroprocessed mineral oil.
 19. The lubricating composition of claim 15,wherein said polyalphaolefin comprises from about 30% to about 60% byweight of the total of said lubricating composition.
 20. The lubricatingcomposition of claim 17, wherein said synthetic hydrocarbon comprisesless than or equal to 70% by weight of the total of said lubricatingcomposition.
 21. The lubricating composition of claim 14, wherein saidester comprises less than or equal to 20% by weight of the total of saidlubricating composition.
 22. The lubricating composition of claim 18,wherein said ester, mineral oil and/or hydroprocessed mineral oilcomprise less than or equal to 20% by weight of the total of saidlubricating composition.
 23. The lubricating composition of claim 1,further comprising one or more of: thickeners, antioxidants, inhibitorpackages, and/or anti-rust additives.
 24. The lubricating composition ofclaim 1, further comprising one or more of: dispersants, detergents,friction modifiers, traction improving additives, demulsifiers,defoamants, chromophores (dyes), and/or haze inhibitors.
 25. Thelubricating composition of claim 23, further comprising one or more of:dispersants, detergents, friction modifiers, traction improvingadditives, demulsifiers, defoamants, chromophores (dyes), and/or hazeinhibitors.
 26. The lubricating composition of claim 1, wherein saidlubricating composition comprises a finished gear oil.
 27. The finishedgear oil of claim 26, wherein the blend of said high viscosity fluidblended with said lower viscosity fluid comprises a major amount of saidfinished gear oil.
 28. The lubricating composition of claim 1, furthercomprising extreme pressure protection and anti-wear additives.
 29. Thelubricating composition of claim 1, comprising an automatic transmissionfluid, manual transmission fluid, transaxle lubricant, gear lubricant,open gear lubricant, enclosed gear lubricant, and/or tractor lubricant.30. The lubricating composition of claim 1, comprising a contact surfacecomprising at least a portion of an automatic transmission, manualtransmission, transaxle, gear, open gear, enclosed gear, and/or tractor.31. An automotive gear lubricating composition comprising: a highviscosity fluid, said high viscosity fluid having a viscosity of greaterthan or equal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt.at 100° C., blended with a lower viscosity fluid, said lower viscosityfluid having a viscosity of less than or equal to 40 cSt. at 100° C.,wherein the final blend of said high viscosity fluid and said lowerviscosity fluid has a viscosity index greater than or equal to
 175. 32.The automotive gear lubricating composition of claim 31, wherein saidhigh viscosity fluid has a viscosity of greater than or equal to 60 cSt.at 100° C.
 33. The automotive gear lubricating composition of claim 31,wherein said high viscosity fluid has a viscosity of less than or equalto 1,000 cSt. at 100° C.
 34. The automotive gear lubricating compositionof claim 32, wherein said high viscosity fluid has a viscosity of lessthan or equal to 1,000 cSt. at 100° C.
 35. The automotive gearlubricating composition of claim 31, wherein said high viscosity fluidhas a viscosity of greater than or equal to 80 cSt. at 100° C.
 36. Theautomotive gear lubricating composition of claim 31, wherein said highviscosity fluid has a viscosity of less than or equal to 300 cSt. at100° C.
 37. The automotive gear lubricating composition of claim 35,wherein said high viscosity fluid has a viscosity of less than or equalto 300 cSt. at 100° C.
 38. The automotive gear lubricating compositionof claim 31, wherein said lower viscosity fluid has a viscosity of lessthan or equal to 10 cSt. at 100° C.
 39. The automotive gear lubricatingcomposition of claim 31, wherein said lower viscosity fluid has aviscosity of less than or equal to 6 cSt. at 100° C.
 40. The automotivegear lubricating composition of claim 38, wherein said lower viscosityfluid has a viscosity of greater than or equal to 1.5 cSt. at 100° C.41. The automotive gear lubricating composition of claim 39, whereinsaid lower viscosity fluid has a viscosity of greater than or equal to1.5 cSt. at 100° C.
 42. The automotive gear lubricating composition ofclaim 31, wherein said viscosity index is greater than or equal to 190.43. The automotive gear lubricating composition of claim 31, whereinsaid high viscosity fluid and said lower viscosity fluid comprise basestocks.
 44. The automotive gear lubricating composition of claim 31,further comprising an ester.
 45. The automotive gear lubricatingcomposition of claim 31, wherein said high viscosity fluid comprises apolyalphaolefin.
 46. The automotive gear lubricating composition ofclaim 31, wherein said high viscosity fluid and said lower viscosityfluid comprise polyalphaolefins.
 47. The automotive gear lubricatingcomposition of claim 31, wherein said lower viscosity fluid comprises asynthetic hydrocarbon.
 48. The automotive gear lubricating compositionof claim 31, further comprising one or more of an ester, mineral oiland/or hydroprocessed mineral oil.
 49. The automotive gear lubricatingcomposition of claim 45, wherein said polyalphaolefin comprises fromabout 30% to about 60% by weight of the total of said automotive gearlubricating composition.
 50. The automotive gear lubricating compositionof claim 47, wherein said synthetic hydrocarbon comprises less than orequal to 70% by weight of the total of said automotive gear lubricatingcomposition.
 51. The automotive gear lubricating composition of claim44, wherein said ester comprises less than or equal to 20% by weight ofthe total of said automotive gear lubricating composition.
 52. Theautomotive gear lubricating composition of claim 48, wherein said ester,mineral oil and/or hydroprocessed mineral oil comprise less than orequal to 20% by weight of the total of said automotive gear lubricatingcomposition.
 53. The automotive gear lubricating composition of claim31, further comprising one or more of: thickeners, antioxidants,inhibitor packages, and/or anti-rust additives.
 54. The automotive gearlubricating composition of claim 31, further comprising one or more of:dispersants, detergents, friction modifiers, traction improvingadditives, demulsifiers, defoamants, chromophores (dyes), and/or hazeinhibitors.
 55. The automotive gear lubricating composition of claim 53,further comprising one or more of: dispersants, detergents, frictionmodifiers, traction improving additives, demulsifiers, defoamants,chromophores (dyes), and/or haze inhibitors.
 56. The automotive gearlubricating composition of claim 31, wherein said automotive gearlubricating composition comprises a finished gear oil.
 57. The finishedgear oil of claim 56, wherein the blend of said high viscosity fluidblended with said lower viscosity fluid comprises a major amount of saidfinished gear oil.
 58. The automotive gear lubricating composition ofclaim 31, further comprising extreme pressure protection and anti-wearadditives.
 59. The automotive gear lubricating composition of claim 31,comprising an automatic transmission fluid, manual transmission fluid,transaxle lubricant, gear lubricant, open gear lubricant, enclosed gearlubricant, and/or tractor lubricant.
 60. The automotive gear lubricatingcomposition of claim 31, comprising a contact surface comprising atleast a portion of an automatic transmission, manual transmission,transaxle, gear, open gear, enclosed gear, and/or tractor.
 61. Anautomotive gear lubricating composition comprising a blend of components(A) and (B), wherein: component (A) comprises a high viscosity fluid,said high viscosity fluid having (i) a viscosity of greater than orequal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt. at 100°C. and, (ii) a viscosity index greater than or equal to 180; andcomponent (B) comprises a lower viscosity fluid, said lower viscosityfluid having a viscosity of less than or equal to 40 cSt. at 100° C.;wherein the final blend of components (A) and (B) has a viscosity indexgreater than or equal to
 175. 62. The automotive gear lubricatingcomposition of claim 61, wherein the final blend of components (A) and(B) has a viscosity index greater than or equal to
 190. 63. Theautomotive gear lubricating composition of claim 61, wherein theviscosity index of component (A) is greater than or equal to
 190. 64.The automotive gear lubricating composition of claim 61, wherein saidhigh viscosity fluid and said lower viscosity fluid comprise basestocks.
 65. The automotive gear lubricating composition of claim 61,further comprising an ester.
 66. The automotive gear lubricatingcomposition of claim 61, wherein said high viscosity fluid comprises apolyalphaolefin.
 67. The automotive gear lubricating composition ofclaim 61, wherein said high viscosity fluid and said lower viscosityfluid comprise polyalphaolefins.
 68. The automotive gear lubricatingcomposition of claim 61, further comprising one or more of an ester,mineral oil and/or hydroprocessed mineral oil.
 69. The automotive gearlubricating composition of claim 66, wherein said polyalphaolefincomprises from about 30% to about 60% by weight of the total of saidautomotive gear lubricating composition.
 70. The automotive gearlubricating composition of claim 65, wherein said ester comprises lessthan or equal to 20% by weight of the total of said automotive gearlubricating composition.
 71. The automotive gear lubricating compositionof claim 68, wherein said ester, mineral oil and/or hydroprocessedmineral oil comprise less than or equal to 20% by weight of the total ofsaid automotive gear lubricating composition.
 72. The automotive gearlubricating composition of claim 61, further comprising one or more of:thickeners, antioxidants, inhibitor packages, and/or anti-rustadditives.
 73. The automotive gear lubricating composition of claim 61,further comprising one or more of: dispersants, detergents, frictionmodifiers, traction improving additives, demulsifiers, defoamants,chromophores (dyes), and/or haze inhibitors.
 74. The automotive gearlubricating composition of claim 72, further comprising one or more of:dispersants, detergents, friction modifiers, traction improvingadditives, demulsifiers, defoamants, chromophores (dyes), and/or hazeinhibitors.
 75. The automotive gear lubricating composition of claim 61,wherein said automotive gear lubricating composition comprises afinished gear oil.
 76. The automotive gear lubricating composition ofclaim 61, further comprising extreme pressure protection and anti-wearadditives.
 77. The automotive gear lubricating composition of claim 61,comprising an automatic transmission fluid, manual transmission fluid,transaxle lubricant, gear lubricant, open gear lubricant, enclosed gearlubricant, and/or tractor lubricant.
 78. The automotive gear lubricatingcomposition of claim 61, comprising a contact surface comprising atleast a portion of an automatic transmission, manual transmission,transaxle, gear, open gear, enclosed gear, and/or tractor.
 79. A methodof preparing a lubricating composition comprising blending a highviscosity fluid, said high viscosity fluid having a viscosity of greaterthan or equal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt.at 100° C., with a lower viscosity fluid, said lower viscosity fluidhaving a viscosity of less than or equal to 40 cSt. at 100° C., whereinthe final blend of said high viscosity fluid and said lower viscosityfluid has a viscosity index greater than or equal to
 175. 80. The methodof claim 79, wherein said high viscosity fluid has a viscosity index of180 or greater.
 81. The method of claim 79, wherein said high viscosityfluid and said lower viscosity fluid comprise base stocks.
 82. Themethod of claim 79, wherein the blend of said high viscosity fluidblended with said lower viscosity fluid comprises a major amount of saidlubricating composition.
 83. The method of claim 79, further comprisingthe step of adding an ester.
 84. The method of claim 79, wherein saidhigh viscosity fluid comprises a polyalphaolefin.
 85. The method ofclaim 79, wherein said lower viscosity fluid comprises a synthetichydrocarbon.
 86. The method of claim 84, further comprising the step ofadding an ester.
 87. The product according to the method of claim 79.88. An automotive gear lubricating composition comprising: a majoramount of a blend of a high viscosity fluid blended with a lowerviscosity fluid, said high viscosity fluid having a viscosity of greaterthan or equal to 40 cSt. at 100° C. and less than or equal to 3,000 cSt.at 100° C., said lower viscosity fluid having a viscosity of less thanor equal to 40 cSt. at 100° C., wherein the final blend has a viscosityindex greater than or equal to
 175. 89. The method of claim 88, whereinsaid high viscosity fluid and said lower viscosity fluid comprise basestocks.
 90. An automotive gear lubricating composition comprising: ahigh viscosity fluid, said high viscosity fluid having a viscosity ofgreater than or equal to 80 cSt. at 100° C. and less than or equal to300 cSt. at 100° C., blended with a lower viscosity fluid, said lowerviscosity fluid having a viscosity of less than or equal to 6 cSt. at100° C. and greater than or equal to 1.5 cSt. at 100° C., wherein thefinal blend of said high viscosity fluid and said lower viscosity fluidhas a viscosity index greater than or equal to
 190. 91. The method ofclaim 90, wherein said high viscosity fluid and said lower viscosityfluid comprise base stocks.